The Influence of Road Geometric Design Elements on Road Traffic Accident from Bedele City to Dedesa River.

Abstract

Road traffic accident are a global problem affecting all parts of society. The major causes of road traffic accident are road user, vehicle condition and road environment. In Ethiopia, road traffic accident has been worsened as the number of vehicles has increased and consequently due to increased traffic flow and conflicts between vehicles and pedestrians. The highway from Bedele to Dedesa, has been experiencing many road traffic accidents. The main objective of this research work was to study the influence of road geometric design elements on road traffic accident. The Methods used on this research were, both qualitative and quantitative method of data analysis, black spot identification has been done. Next, interview for different stakeholders and comparison of the geometric data to the standard has been carried out. Finally, site inspection has been conducted. There were eight black spot locations. Mine (25), Bedele ganda 01 (17), Lilkee qararo (26), Jisa (18), Saxa (32), Sidan (18), Adebi (20) and Demo (21) were the black spot locations which have the highest priority value. These black spot location geometric parameters were found below the minimum requirements. The required curve widening (0.6-1.2m) is not provided for these locations. The radius used at Mine, Lilkee qararo, Jisa, Saxa Adebi and Demo were below the minimum requirement. There were also a high gradient at Lilke qararo (9%) and Jisa (8.3%). In addition, the road length had lost all types of road markings, presence of vegetation obstruction, pavement deterioration, existence of sharp horizontal curves, occurrence of horizontal curve in steep vertical grade, absence of delineators with curve widening and sign posts. The counter measures given were: - the installation of road side delineator, curve widening, the provision of sufficient site clearance and avoid obstruction, the installation of traffic signals and the re furnishing of pavement marking are measures that should be taken to minimize road traffic accident. As a long lasting solution, revision of road geometry must be done.